Compilare: user.cpp: In function ‘int main()’: user.cpp:14:29: warning: format ‘%s’ expects argument of type ‘char*’, but argument 3 has type ‘char (*)[2000001]’ [-Wformat=] fscanf(fi,"%s " ,&str); ^ user.cpp:19:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[str[n]]++; ^ user.cpp:11:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&t); ^ user.cpp:14:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%s " ,&str); ^